This invention relates generally to door lock assemblies and more particularly to a spring catch for attaching removable levers and knobs to a lock chassis.
In locksets, removable knobs and levers are usually attached by a steel plate or catch. The catch is positioned within a steel sleeve, commonly referred to as a spindle, and oriented perpendicular to the longitudinal axis of the spindle. The catch is spring loaded (or biased in one direction) such that a leading edge of the catch projects through an opening in the spindle and extends beyond the outer diameter of the spindle.
To attach the knob to the spindle, the catch is pressed inwardly into the spindle (under spring load) and the knob is inserted over the spindle until a slot in the knob is aligned with the catch. In a free condition and with the force of the spring, an edge of the catch extends back out of the spindle and engages the slot in the knob. This edge, when engaged into the knob slot, axially retains the knob to the lock chassis. Depressing the catch allows removal of the knob.
Lock manufacturers use a variety of designs to achieve this spring load that provides the bias to the catch. One common design uses a section of straight music wire that is first "woven" through three holes in the spindle and fed through a hole in the catch and then finally detented or deformed such that it exerts a spring load to the catch. Another design is illustrated in U.S. Pat. No. 4,342,478 which discloses a wire form spring that exerts a load from the inside diameter of the spindle to the catch.
One problem with known catch designs is the complex operations necessary to install the catch, either during manufacturing or in the field in the event the wire breaks. Frequently, these known designs do not lend themselves to automation.
The foregoing illustrates limitations known to exist in present handle catches. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.